In this project we are using fluorescence spectroscopy to characterize human and animal eye lenses. One goal is to develop optical fluorescence as a diagnostic tool for determining the state of health of human lenses, with particular emphasis on the effects of aging and cataracts on the fluorescence properties. A second goal is to use fluorescence spectroscopy in conjunction with biochemical protein separation techniques to determine the molecular nature and state of binding of fluorescent compounds in lens and their relation (if any) to cataractogenesis. We are also studying the photochemistry and photobiology of human and animal lenses in culture media. These studies are being done mostly in vitro, but some work with laboratory animals is in progress.